1. Field of the Invention
The present invention relates to the field of textile technology and, more particularly, relates to a method and an apparatus for in-line color measurement of slivers.
2. Description of Background and Other Information
Color measurement of various materials is a widely used technique. Thus, color sensors for a large number of applications are to be found on the market. They may be used for laboratory methods and for in-line methods of process monitoring and control. Such color measurements do not generally cause significant problems where compact materials with smooth surfaces are concerned. However, for loose materials (e.g., powder), strongly porous materials (e.g., sintering bodies), a standardized preparation of the samples is required. Therefore, materials like cotton wool, for example, only provide reproducible and meaningful color measurement results if such materials are brought to the color sensor in a form which is as standardized as possible. In the field of textile technology, such standardized color measurements are also performed on stationary samples of fiber material.
In the various stages of textile production, color measurements are performed and the measured data are then utilized for process monitoring and control. In the area of the preparatory machine, the in-line color measurement of slivers, in particular, would be preferable. However, such measurements have not yet been performed or perfected due to the fact that, presently, no method is known with which one could perform the manipulation in continuously moving slivers, which is necessary for the standardized sample preparation, without permanently changing the slivers or disturbing the process. A permanent change in the sliver to be measured is, under all circumstances, not acceptable, neither with regard to the sliver's mass per unit of length, its density, the orientation of the slivers, nor its randomly laid layer.